versão impressa ISSN 0006-8705
GARCIA BLANCO, H. et al. Fertility of some soils in alluvial plains of the Paraíba valley. Bragantia [online]. 1964, vol.23, n.unico, pp. 55-63. ISSN 0006-8705. http://dx.doi.org/10.1590/S0006-87051964000100006.
A study dealing with the fertility of three soils from alluvial plains in the Paraiba River Valley, State of São Paulo, was carried out in greenhouse tests, with rice (of the Iguape-agulha variety) cultivated in pots of 6.0 kg soil capacity. The samples were collected down to 20 cm depth from the following monotype soils series: Corruçá, Brejão and Avareí. The former is an alluvial clay soil and the latter an organic one representing stratified muck and peat; the Brejão series is also organic soil but has an intermediate, organic and clay, texture. The experiment was designed to investigate these soils' needs for the NPK nutrients. In an extra treatment the needs for the minor elements were investigated too. The results obtained in these experiments indicated that the fertility levels based on chemical analyses and applied to fertilization practice to other well drained soils of the State are not satisfactory for the soils in question. A significant favorable response to nitrogen was shown by all the soils studied though they held high content of this element. The response to potassium was non-significant to the heavier soil and significant to the other ones. The addition of phosphorus had a sensible favorable effect in the organic soil and had its intensity decreased in the alluvial clay soil; in the soil of intermediate texture (Brejão series) it was not significant. The application of minor elements had non-significant effects.